The unit goes into the steps in some detail and focuses on being accessible to those just starting out with Salesforce.

Above is a quiz question from the Trailhead Playground Management module. It's technically correct as per the instructions in that module, but I don't think it is the best approach and from what I've seen is a common source of confusion.

I'd like to present an alternative approach. It might not be as accessible, but it does bypass a number of steps that can lead to further complications. So, without any more fanfare I present the Deployment Fish approved way of installing packages and apps into a Salesforce Org.

Obtain the package installation URL:Just right click on the package link and Copy Link Address. The approach will vary based on the browser, but there should be a fairly simple way to extract the link.https://login.salesforce.com/packaging/installPackage.apexp?p0=04tB00000009UeX

Copy everything from that URL except for the domain:/packaging/installPackage.apexp?p0=04tB00000009UeXThe ID with the 04t keyprefix is the important part here. That identifies what package/app you are installing.

Log into the org/playground where you want to install the package

Paste the content copied from Step 2 after the domain.URL before:https://curious-raccoon-286917-dev-ed.lightning.force.com/one/one.app#/homeURL after:https://curious-raccoon-286917-dev-ed.lightning.force.com/packaging/installPackage.apexp?p0=04tB00000009UeX

Follow the remaining prompts.

AppExchange packages

A similar technique can be used with the AppExchange. The only catch here is they make it a bit harder to get the package version id. Lets use the Salesforce Adoption Dashboards as an example app.

You will end up at a login page. DO NOT LOGIN HERE!Look closely at the URL. You will see the package version ID.
In my case it was https://login.salesforce.com/?startURL=%2Fpackaging%2FinstallPackage.apexp%3Fp0%3D04t410000009jsfAAA%26newUI%3D1%26src%3Du

Append that ID to /packaging/installPackage.apexp?p0= on your actual target org as you did in step 4 of the URL Manipulation Maneuver./packaging/installPackage.apexp?p0=04t410000009jsfAAA

These steps may look complicated at first, but in reality it is a small cut-and-paste job to find the package version Id. Once you have the Id the rest of the process becomes much simpler. You could even look at automating the process using the SalesforceDX CLI.

The real benefit is for those that routinely work between multiple orgs. It provides more certainty that you are installing in the org you intended to. Plus you don't even need to figure out your Trailhead playgrounds authentication details.

¯\_(ツ)_/¯When you jump between multiple orgs all day directly changing the URL often seems like the easiest way to target the correct org. Way to often the auth process sends me into an unexpected org.

A few moments of playing on the /changemgmt/monitorDeploymentsDetails.apexp page reveals that JSON data about the current deployment status flows through SfdcApp.MonitorDeployment.InProgressComponent.refreshInProgressSection. We can call the same function ourselves and manipulate the totalComponentsCount and succeededComponentsCount data as required: